A furious row has erupted after a Celtic footballer was given a formal caution for blessing himself during an Old Firm game. Artur Boruc, the Polish goalkeeper, was accused of inciting violence and angering rival supporters by making the gesture in front of Rangers fans at Ibrox stadium in Glasgow.

The Crown Office's decision to give him an official warning has provoked a strong reaction, with politicians and church leaders saying it will make Scotland the 'laughing stock of the world' as players often cross themselves in football grounds. Boruc was cautioned for a breach of the peace after complaints were made by Rangers fans following the game in February.

The Catholic church has condemned Scottish prosecutors, with spokesman Peter Kearney saying many Catholics would feel subject to persecution following the decision. 'It's an alarming development, especially since the Sign of the Cross is globally accepted as a gesture of religious reverence,' he said. 'It was commonplace throughout the World Cup. It is extremely regrettable that Scotland seems to have made itself one of the few countries in the world where this simple religious gesture is considered an offence.'

The Crown Office said a caution was issued as an alternative to prosecution. A spokesman said that as Boruc made the gesture before a crowd in the charged atmosphere of an Old Firm game it constituted a breach of the peace and had 'provoked alarm'.

But many politicians were also critical. Nationalist leader Alex Salmond said the 'ludicrous' move was the type of action which brought the law and legal system into disrepute. 'The procurator fiscal and the Crown Office are acting in a way that will inflame rather than reduce religious antagonism,' he said.

Liberal Democrat MSP Donald Gorrie said he felt the situation could have been addressed by talking to Boruc privately. 'I think they were wrong to focus on the crossing rather than the whole performance, as described to me by quite sensible people who were definitely wound up by it as they were intended to be, and he shouldn't do that,' he added.

Neither club has commented on the cautioning, but Eddie Toner, a former general secretary of the Celtic Supporters Association, expressed fury with the club, claiming it had 'hung Boruc out to dry'.

'Perhaps those who made the complaint to the police should have a long hard look at themselves, as it seems that it is they who have the sectarian problem,' he added. 'The gesture is made by sportsmen and women all over the world, but bizarrely only seems to cause offence here in Scotland.'

However, Rangers Supporters Group said it was 'disappointing' Celtic did not take action after the game. Stephen Smith, spokesman for the group, added: 'Professional footballers are meant to set an example. What he did was deliberately provocative and completely done to wind up the fans.'

The fixture takes place in a highly charged atmosphere and has produced no shortage of controversy. Time, the international news magazine, once described it as 90 minutes of sheer hatred.